Field of the Invention
The present invention relates to a pneumatic tire including a characteristic tread surface to exhibit good irregular wear resistance, and is especially advantageous as a heavy-loading pneumatic tire.
Description of the Related Art
A tread surface of a pneumatic tire is provided with a plurality of main grooves continuously extending in a tire circumferential direction, and land portions such as ribs or block rows, which are divided by the main grooves, to form various tread patterns depending on required tire performance and use conditions. Because the block rows have lower stiffness than the rib, a block-based pattern exhibits lower irregular wear resistance than a rib-based pattern. To counter the problem, stiffness can be ensured by decreasing a depth of the lateral grooves that divide the blocks. In this case, however, traction performance tends to degrade after a middle wear stage.
To enhance irregular wear resistance while ensuring traction performance after the middle wear stage, the tire needs to have the configuration capable of suppressing excessive deformation of the blocks as well as achieving a traction effect after the middle wear stage. Patent Documents 1 to 5 disclose pneumatic tires having various different tread patterns but having no such a configuration, and fail to disclose any means for solving the above problem.